1. Field of the Invention
The invention is related to electrically conductive polymer-metal alloy blends and in particular to an electrically conductive polymer-metal alloy blend having an interpenetrating polymer network.
2. Prior Art
Metals and/or carbon black are often combined with polymers to increase their electrical and thermal conductivities while maintaining ease of processing and low density such as taught by Meyer in U.S. Pat. No. 3,976,600. Usually the conductive material is in the form of flakes, fibers, or powder that are dispersed at fairly high concentrations throughout the polymer matrix. However, the electrical conductivity achieved for a given amount of added conductive material is low due to the discontinuities of the conducting phase. Alternatively it is known to use a wire mesh to provide a continuous electrical conductivity through the polymer-metal structure and achieve higher conductivity, but this approach suffers from limited applications and processability.
Coler in U.S. Pat. No. 2,761,854 discloses a different method for making high conductivity polymer-metal alloys in which the polymer powder particles are precoated with a metal film. The metal film coating on the polymer particles form a nearly continuous metallic network within the processed structure. The problem with this process is that metal films separate the individual polymer particles substantially weakening the physical structure of the molded structure or article.
The invention is a high conductivity polymer-metal alloy blend using a block copolymer as taught by Gergen et al in U.S. Pat. No. 4,088,626 or a particulate loaded polymer having non-Newtonian behavior as disclosed in patent application Ser. No. 411,922 filed June 28, 1982 and now abandoned.